python系统学习：第三周之简单的三级菜单

# 三级目录info = {    # 一级    ‘ShanXi‘: {        # 二级        ‘JieXiu‘: {            # 三级            ‘XiaoSongQv‘: [‘Burn here!‘],            ‘SanSchool‘: [‘Study here‘]        }    },    ‘BeiJing‘: {        ‘ChaoYang‘: {            ‘XianNinghou‘: [‘Live here!‘]        },        ‘BeiYuan‘: {            ‘TieJian‘: [‘Work Here!‘]        }    }}# 三级目录的跳转# 定义标志flag = Falsewhile not flag:    for name1 in info:        print(name1)    # 选择1    choice = input(‘>>where?‘)    # 判断是否存在    if choice in info:        # 判断成功打印第二层        while not flag:            for name2 in info[choice]:                print(name2)            # 选择            choice2 = input(‘>>where?‘)            # 判断是否存在            if choice2 in info[choice]:                # 判断成功打印第三层                while not flag:                    for name3 in info[choice][choice2]:                        print(name3)                    choice3 = input(‘>>where?‘)                    if choice3 in info[choice][choice2]:                        for name4 in info[choice][choice2][choice3]:                            print(name4)                        choice4 = input(‘最后一层，b返回,q退出！‘)                        if choice4 == ‘b‘:                            pass  # 占位符  我什么都不做                        elif choice4 == ‘q‘:                            flag = True                    elif choice3 == ‘b‘:                        break                    elif choice3 == ‘q‘:                        flag = True            elif choice2 == ‘b‘:                break            elif choice2 == ‘q‘:                flag = True    # 输入B返回    elif choice == ‘b‘:        pass    # 输入q退出    elif choice == ‘q‘:        flag = True

或许你认为这个写法比较弱智，但是学习代码都是从麻烦到简单，学会了最原始的写法，能更好的了解运行机制，等后面学了函数等，就变得简单了。

原文地址：https://www.cnblogs.com/niushichong/p/10009133.html